She says the work advances on earlier studies by Guille that show first-year medical interns in the US have a 25 per cent chance of developing depression or anxiety.

"Guille wanted to see if you could do something to prevent the development of these conditions," she says.

The trial, held between April 2009 and June 2010, involved 108 medical interns from Yale University and the Medical University of Southern California aged between 23 and 40 years.

One group used the online mental health program, MoodGYM, which includes modules of cognitive behaviour therapy, during a four-week period.

The second group received emails with information about depression and contacts.

Christensen says the trial shows interns using the online mental health modules were 3.5 times less likely to develop an incidence of depression than their counterparts.

This correlated to a 62.6% reduction in incidences of depression among the interns.

Christensen says while the trial sample is small it shows the potential for the use of online mental health strategies.

"We are looking at people whose likelihood of developing depression is going to increase … and this shows that MoodGYM works [in turning that around]," she says.

"I think it is an interesting start."

Christensen says Guille now plans to replicate the study with a larger group of US interns.

'As good as' telephone

In the second trial, which is ongoing, participants undertake a 10-week multimedia online anxiety intervention.

Christensen says the participants were chosen randomly via the Australian electoral roll and then screened for symptoms of anxiety.

The participants were divided into five groups with three groups receiving the dedicated mental health online program e-couch and two a more generic health program, HealthWatch.

Among e-couch users, the amount of contact with people was varied.

Christensen says this aspect of the study is important because it will help determine what makes the online program most effective.

"I suspect the results will show emails will be as good as a telephone call and it might be that e-couch on its own is good enough," she says.

To date 138 people have undertaken the trial, with the researchers aiming for 500 participants.

Christensen says initial results show "differential effects" between the groups.

"The results are very positive that e-couch is more effective than HealthWatch," she says. "One of the most interesting things is there is a significant decrease in suicide ideation as a result of e-couch."